In laser triangulation were detected, with a finely focused laser beam to scan on the surface of the wafer, optical system will be reflected laser focus to detector (Fig. 1). 3D laser triangulation is used to detect the morphology of micro bumps, and it has obvious advantages in precision, speed and detection. The detection technology is currently facing challenges including the interval between the bump size and convex points are very small, and in the whole wafer littered with millions of bump.

Fig. 1 laser triangulation of the convex point is calculated by the reflection of the laser beam.

Laser triangulation was detected in the probe laser beam scanning process to obtain the silicon substrate and the bump at the top of the data, because of it of the convex surface and the periphery of the substrate only a single scan, so that you can to eliminate multiple scans of the error and the uncertainty inherent in different height. Single sweep method can detect the Z direction with high accuracy and high precision. The performance of the method can reach the theoretical resolution of the detector, which is smaller than the current size of the salient points.

激光三角检测术除了具有很高的检测准确度和精确度以外，它还具有与生产能力相当的检测速度，数据的采集速率足以满足大生产过程中对整个圆片进行检测的需求。在全晶圆检测模式中，系统通过一系列相近的线扫描来覆盖整个圆片，单个扫描为600μm宽的长条形区域，所产生的典型数据密度为40,000个数据点/mm2（图2）。变换采样密度可对检测过程进行优化，以最大程度地满足某些特别应用对分辨率、精确度和产量的要求，而且还可以很容易地满足将来凸点直径和节距进一步减小后对检测的要求。数据密度能够根据所需的特征尺寸和产量进行增加或减小。该系统可以在高产量下实现全晶圆的检测，通过实施仅检测指定芯片的采样计划，就有可能在维持检测统计有效性的情况下来增加检测产量。

Laser triangulation was detected except with very high detection accuracy and precision, it also has the detection speed and production capacity, the data acquisition rate enough to meet the needs of production process of the whole wafer detection. In the full wafer detection mode, the system through a series of similar line scanning to cover the entire wafer and scanning a single for 600 mu m wide strip region, the typical data generated by density for 40000 data points / mm2 (Figure 2). Transform sampling density to optimize the detection process, to maximize meet the requirements of some special application of resolution, accuracy and yield, but also can easily meet future bump diameter and section from further reduced after the detection requirements. The data density can be increased or reduced according to the required feature size and output. The system can realize the whole wafer detection in high output, and it is possible to increase the detection output by the implementation of the sampling plan which only detects the specified chip.